78 ANIMAL MECHANISM. 



under tlie influence of more extended movements, acquire a 

 greater length ? Can we see a displacement of the tendinous 

 attachments of the muscles to the skeleton, under the influence 

 of changes in the force of muscular traction ? Such is the second 

 problem which we propose to ourselves, and which experiment 

 should be called on to deterniiue. 



Fig. 18.— Muscles of the thigh of the Coaita Rectus interiius, inserted 

 at a distance from the knee, almost entirely without tendon. The 

 sartorius having its superior attachment very far from the coxo-femoral 

 articulation, has very extended movements ; it possesses in consequenje 

 a great length of red fibre, and not of tendon. 



THE DEVELOPMENT THEORY. 



The natural sciences have derived at the present day a 

 great impulse from the influence of the ideas of Darwin. 



